Using OER to Profile the Traffic Classes

First Published: January 29, 2007

Last Updated: November 20, 2009

This module describes how Optimized Edge Routing (OER) profiles the traffic classes. To optimize traffic routing, subsets of the total traffic must be identified, and these traffic subsets are named traffic classes. The OER master controller can profile traffic classes either by manual configuration on the master controller, or by automatic learning on the basis of parameters such as throughput or delay characteristics of traffic on the border routers. Automatic learning requires traffic class parameters to be configured on the master controller.

Note If you are running Cisco IOS Release 12.4(15)T or a later release, please refer to the "Using Performance Routing to Profile the Traffic Classes" module for the latest configuration information and tasks introduced for Performance Routing. Performance Routing (PfR) is an extension of the Optimized Edge Routing (OER) technology and the commands and command modes for PfR use the oer naming convention.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Using OER to Profile the Traffic Classes" section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

•Cisco Express Forwarding (CEF) must be enabled on all participating devices. No other switching path is supported, even if otherwise supported by PBR.

Restrictions for Using OER to Profile the Traffic Classes

If any of the border routers is a Cisco Catalyst 6500 switch or a Cisco 7600 series router, there are some hardware constraints and the master controller will set the monitoring mode to special where only the throughput method of learning is used to profile the traffic classes. If both delay and throughput are configured, the master controller will ignore the delay configuration. For more details about the special monitoring mode, see the "Measuring the Traffic Class Performance and Link Utilization Using OER" module for more details.

Information About Using OER to Profile the Traffic Classes

To configure the master controller to profile traffic classes, you should understand the following concepts:

OER Traffic Class Profiling

Before optimizing traffic, OER has to determine the traffic classes from the traffic flowing through the border routers. To optimize traffic routing, subsets of the total traffic must be identified, and these traffic subsets are named traffic classes. The list of traffic classes entries is named a Monitored Traffic Class (MTC) list. The entries in the MTC list can be profiled either by automatically learning the traffic flowing through the device or by manually configuring the traffic classes. Learned and configured traffic classes can both exist in the MTC list at the same time. The OER profile phase includes both the learn mechanism and the configure mechanism. The overall structure of the OER traffic class profile process and its component parts can be seen in Figure 1.

Figure 1 OER Traffic Class Profiling Process

The ultimate objective of this phase is to select a subset of traffic flowing through the network. This subset of traffic—the traffic classes in the MTC list—represents the classes of traffic that need to be routed based on the best performance path available.

More details about each of the components in Figure 1 are contained in the following concepts:

OER Automatic Traffic Class Learning

OER can automatically learn the traffic classes while monitoring the traffic flow through border routers. Although the goal is to optimize a subset of the traffic, you may not know all the exact parameters of this traffic and OER provides a method to automatically learn the traffic and create traffic classes by populating the MTC list. Several features have been added to OER since the original release to add functionality to the automatic traffic class learning process.

Within the automatic traffic class learning process there are now three components. One component describes the automatic learning of prefix-based traffic classes, the second component describes automatic learning of application-based traffic classes, and the third component describes the use of learn lists to categorize both prefix-based and application-based traffic classes. These three components are described in the following sections:

Prefix Traffic Class Learning Using OER

The OER master controller can be configured, using NetFlow Top Talker functionality, to automatically learn prefixes based on the highest outbound throughput or the highest delay time. Throughput learning measures prefixes that generate the highest outbound traffic volume. Throughput prefixes are sorted from highest to lowest. Delay learning measures prefixes with the highest round-trip response time (RTT) to optimize these highest delay prefixes to try to reduce the RTT for these prefixes. Delay prefixes are sorted from the highest to the lowest delay time.

OER can automatically learn two types of prefixes:

•outside prefix—An outside prefix is defined as a public IP prefix assigned outside the company. Outside prefixes are received from other networks.

•inside prefix—An inside prefix is defined as a public IP prefix assigned to a company. An inside prefix is a prefix configured within the company network.

In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the ability to learn inside prefixes was introduced. Using BGP, OER can select inside prefixes to support best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system. In prior releases, only outside prefixes were supported. Company networks advertise the inside prefixes over the Internet using an Internet service provider (ISP) and receive advertisements for outside prefixes from an ISP.

Note Although OER can learn an inside prefix, OER will not try to control an inside prefix unless there is an exact match in the BGP routing information base (RIB) because OER does not advertise a new prefix to the Internet.

Automatic prefix learning is configured in OER Top Talker and Top Delay learning configuration mode. The learn command is used to enter this mode from OER master controller configuration mode. When automatic prefix learning is enabled, prefixes and their delay or throughput characteristics are measured on the border routers. Performance measurements for the prefix-based traffic classes are reported to the master controller where the learned prefixes are stored in the MTC list.

Prefixes are learned on the border routers through monitoring the traffic flow using the embedded NetFlow capability. All incoming and outgoing traffic flows are monitored. The top 100 flows are learned by default, but the master controller can be configured to learn up to 2500 flows for each learn cycle. In Cisco IOS Release 12.4(20)T, 12.2(33)SRE, and later releases, the limit of 5000 prefixes that can be controlled by a master controller was removed. In Cisco IOS Release 12.4(15)T, 12.2(33)SRB, 12.2(33)SXH, and earlier releases, the master controller can control a maximum of 5000 prefixes.

The master controller can be configured to aggregate learned prefixes based on type, BGP or non-BGP (static). Prefixes can be aggregated based on the prefix length. Traffic flows are aggregated using a /24 prefix length by default. Prefix aggregation can be configured to include any subset or superset of the network, from single host route (/32) to a major network address range. For each aggregated prefix, up to five host addresses are selected to use as active probe targets. Prefix aggregation is configured with the aggregation-type command in OER Top Talker and Delay learning configuration mode.

Application Traffic Class Learning Using OER

In the first release of OER, Cisco IOS Release 12.3(8)T, only Layer 3 prefixes could be learned. In subsequent releases, Layer 4 options such as protocol or port numbers were added as filters to the prefix-based traffic class. The protocol and port numbers can be used to identify specific application traffic classes; protocol and port number parameters are monitored only within the context of a prefix and are not sent to the master controller database (MTC list). The prefix that carries the specific traffic is then monitored by the master controller. In Cisco IOS Release 12.4(9)T, Release 12.2(33)SRB, and later releases, application traffic class learning supports Differentiated Services Code Point (DSCP) values in addition to protocol and port numbers, and these Layer 4 options are entered in the MTC list.

Port and Protocol Based Prefix Learning by OER

In Cisco IOS Release 12.3(11)T, Release 12.2(33)SRB, and later releases, prefix learning on the basis of port numbers or protocols was introduced. This feature allows you to configure the master controller to filter the prefix-based traffic class based on the protocol number or the source or destination port number, carried by TCP or UDP traffic. This feature provides a very granular filter that can be used to further optimize prefixes learned based on throughput and delay. The traffic classes sent to the MTC list on the master controller, however, only contain the prefix information, not the protocol and port numbers.

Port and protocol based prefix learning allows you to optimize or exclude traffic streams for a specific protocol or the TCP port, UDP port, or range of port numbers. Traffic can be optimized for a specific application or protocol. Uninteresting traffic can be excluded, allowing you to focus router system resources, and reduce unnecessary CPU and memory utilization. In cases where traffic streams need to be excluded or included over ports that fall above or below a certain port number, the range of port numbers can be specified. Port and protocol prefix based learning is configured with the protocolcommand in OER Top Talker and Top Delay learning configuration mode.

In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the ability to filter and aggregate application traffic by DSCP value, port number or protocol was introduced. Traffic classes can be defined by a combination of keys comprising of protocol, port numbers, and DSCP values. The ability to filter out traffic that is not required, and the ability to aggregate the traffic in which you are interested, was introduced. Information such as protocol, port number, and DSCP value is now sent to the master controller database in addition to the prefix information. The new functionality allows OER to both actively and passively monitor application traffic. Using new CLI and access lists, OER can be configured to automatically learn application traffic classes.

Learn List Configuration Mode

In Cisco IOS Release 12.4(15)T, a new configuration mode named learn list was introduced. Learn lists are a way to categorize learned traffic classes. In each learn list, different criteria including prefixes, application definitions, filters, and aggregation parameters for learning traffic classes can be configured.

If you are running Cisco IOS Release 12.4(15)T or a later release, please refer to the "Using Performance Routing to Profile the Traffic Classes" module for learn list configuration information and tasks introduced for Performance Routing. Performance Routing (PfR) is an extension of the Optimized Edge Routing (OER) technology and the commands and command modes for PfR use the oer naming convention.

OER Manual Traffic Class Configuration

OER can be manually configured to create traffic classes for monitoring and subsequent optimizing. Automatic learning generally uses a default prefix length of /24 but manual configuration allows exact prefixes to be defined. Within the manual traffic class configuration process there are two components— manually configuring prefix-based traffic classes and manually configuring application-based traffic classes, both of which are described in the following sections:

Prefix Traffic Class Configuration Using OER

A prefix or range of prefixes can be selected for OER monitoring by configuring an IP prefix list. The IP prefix list is then imported into the MTC list by configuring a match clause in an OER map. An OER map is similar to an IP route map. IP prefix lists are configured with the ip prefix-listcommand and OER maps are configured with the oer-map command in global configuration mode.

The prefix list syntax operates in a slightly different way with OER than in regular routing. The ge keyword is not used and the le keyword is used by OER to specify only an inclusive prefix. A prefix list can also be used to specify an exact prefix.

A master controller can monitor and control an exact prefix of any length including the default route. If an exact prefix is specified, OER monitors only the exact prefix.

A master controller can monitor and control an inclusive prefix using the le keyword and the le-value argument set to 32. OER monitors the configured prefix and any more specific prefixes (for example, configuring the 10.0.0.0/8 le 32 prefix would include the 10.1.0.0/16 and the 10.1.1.0/24 prefixes) over the same exit and records the information in the routing information base (RIB).

Note Use the inclusive prefix option with caution in a typical OER deployment because of the potential increase in the amount of prefixes being monitored and recorded.

An IP prefix list with a deny statement can be used to configure the master controller to exclude a prefix or prefix length for learned traffic classes. Deny prefix list sequences should be applied in the lowest OER map sequences for best performance. In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the master controller can be configured to tell border routers to filter out uninteresting traffic using an access list.

Note IP prefix lists with deny statements can be applied only to learned traffic classes.

Two types of prefix can be manually configured for OER monitoring using an IP prefix list:

•outside prefix—An outside prefix is defined as a public IP prefix assigned outside the company. Outside prefixes are received from other networks.

•inside prefix—An inside prefix is defined is defined as a public IP prefix assigned to a company. An inside prefix is a prefix configured within the company network.

In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the ability to manually configure inside prefixes was introduced. Using BGP, OER can be configured to select inside prefixes to support best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system. In prior releases, only outside prefixes were supported. Company networks advertise the inside prefixes over the Internet using an Internet service provider (ISP) and receive advertisements for outside prefixes from an ISP.

Note Although an inside prefix can be manually configured for OER monitoring, OER will not try to control an inside prefix unless there is an exact match in the BGP routing information base (RIB) because OER does not advertise a new prefix to the Internet.

Application Traffic Class Configuration Using OER

In the first release of OER, Cisco IOS Release 12.3(8)T, only Layer 3 prefixes could be manually configured during the OER profile phase. In Cisco IOS Release 12.4(2)T, 12.2(33)SRB, and later releases, support for OER application-aware routing for policy-based routing (PBR) was introduced. Application-aware routing allows the selection of traffic for specific applications based on values in the IP packet header, other than the Layer 3 destination address through a named extended IP access control list (ACL). Only named extended ACLs are supported. The extended ACL is configured with a permit statement and then referenced in an OER map. The protocol and port numbers can be used to identify specific application traffic classes, but protocol and port number parameters are monitored only within the context of a prefix, and are not sent to the MTC list. Only the prefix that carries the specific application traffic is profiled by the master controller. With application-aware routing support, active monitoring of application traffic was supported. Passive monitoring of application traffic was introduced in Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, with application traffic class configuration support of the profiling of DSCP values as well as protocol and port numbers. DSCP values, port numbers, and protocols in addition to prefixes, are all now stored in the MTC list.

In Cisco IOS Release 12.4(15)T, new static application mapping was introduced under OER map configuration mode to simplify the configuration of traffic classes. If you are running Cisco IOS Release 12.4(15)T or a later release, please refer to the "Using Performance Routing to Profile the Traffic Classes" module for static application mapping configuration information and tasks introduced for Performance Routing. Performance Routing (PfR) is an extension of the Optimized Edge Routing (OER) technology and the commands and command modes for PfR use the oer naming convention.

How to Configure OER to Profile the Traffic Classes

An OER master controller can be configured to automatically learn the traffic classes, or the traffic classes can be manually configured. Two types of traffic classes—to be automatically learned or manually configured—can be profiled:

Note In Cisco IOS Release 12.4(15)T, the introduction of learn lists allows traffic classes that are automatically learned by OER to be categorized into separate learn lists to which different OER policies can be applied. If you are running Cisco IOS Release 12.4(15)T or a later release, please refer to the "Using Performance Routing to Profile the Traffic Classes" module for learn list configuration information and tasks introduced for Performance Routing. Performance Routing (PfR) is an extension of the Optimized Edge Routing (OER) technology and the commands and command modes for PfR use the oer naming convention.

Configuring OER to Automatically Learn Prefix-Based Traffic Classes

Perform this task to configure an OER master controller to automatically learn prefixes to be used as traffic classes to be entered in the MTC list. This task is performed on the master controller shown in Figure 2.

Figure 2 Network Diagram of OER Master Controller and Border Routers

Thelearncommand is entered in OER master controller configuration mode and is required to enter OER Top Talker and Top Delay configuration mode. This task configures prefix learning based on the highest outbound throughput or the highest delay time, and one or both of these parameters must be specified. Optional configuration parameters such as learning period timers, maximum number of prefixes, and an expiration time for MTC list entries are also shown.

Note If any of the border routers is a Cisco Catalyst 6500 switch or a Cisco 7600 series router, there are some hardware constraints and the master controller will set the monitoring mode to special where only the throughput method of learning is used to profile the traffic classes. Do not configure Step 5 (the delay command) of this task if any of the border routers is a Cisco Catalyst 6500 switch or a Cisco 7600 series router. For more details about the special monitoring mode, see the "Measuring the Traffic Class Performance and Link Utilization Using OER" module.

In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the OER BGP inbound optimization feature introduced the ability to automatically learn inside prefixes to support best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system.

Perform this task to configure an OER master controller to automatically learn inside prefixes to be used as traffic classes to be entered in the MTC list. This task is configured at the master controller and introduces the inside bgp command used in OER Top Talker and Top Delay configuration mode. This task configures automatic prefix learning of the inside prefixes (prefixes within the network). Optional configuration parameters such as learning period timers, maximum number of prefixes, and an expiration time for MTC list entries are also shown.

Prerequisites

•Before configuring this task, BGP peering for internal and external BGP neighbors must be configured.

•This task requires Cisco IOS Release 12.4(9)T, 12.2(33)SRB, or later release to be running on the master controller and border routers.

SUMMARY STEPS

1. enable

2. configure terminal

3. oer master

4. learn

5. inside bgp

6. monitor-period minutes

7. periodic-interval minutes

8. prefixes number

9. expire after {sessionnumber| timeminutes}

10. end

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

oer master

Example:

Router(config)# oer master

Enters OER master controller configuration mode to configure a router as a master controller and to configure global operations and policies.

Configuring OER to Automatically Learn Prefix-Based Traffic Classes Using Protocol or Port Number

Perform this task to configure an OER master controller to learn traffic classes to be entered in the MTC list based on prefixes but filtered by the protocol or port number. This task is performed on a master controller. Thelearncommand is entered in OER master controller configuration mode and is required to enter OER Top Talker and Top Delay configuration mode. This task configures prefix learning based on the highest outbound throughput or the highest delay time and one or both of these parameters must be specified. After the prefix has been learned, a protocol or port number can be specified to create a subset of traffic classes. Optional configuration parameters such as learning period timers, the maximum number of prefixes, and an expiration time for MTC list entries are also shown.

Prerequisites

This task requires Cisco IOS Release 12.3(11)T, 12.2(33)SRB, or later release, to be running on the master controller and border routers.

Configures the master controller to learn prefixes based on a protocol number, TCP or UDP port number, or a range of port numbers.

•Filtering based on a specific protocol is configured with the protocol-number argument.

•TCP or UDP based filtering is enabled by configuring the tcp or udpkeyword.

•Port based filtering is enabled by configuring theportkeyword. Port number ranges can be filtered based on greater-than or equal-to and less-than or equal-to filtering, or can be filtered by specifying a starting and ending port numbers with the range keyword.

•Destination or source port-based filtering is enabled by configuring the dst or src keywords.

•The example configures a master controller to learn prefixes from a database during each monitoring period. The database traffic is identified by a range of port numbers.

Step 13

end

Example:

Router(config-oer-mc)# end

Exits OER Top Talker and Top Delay learning configuration mode, and returns to privileged EXEC mode.

Perform this task at the master controller to define the application traffic flow fields that OER can use to automatically learn traffic classes to be entered in the MTC list. In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, traffic class commands were introduced to help define the application traffic classes. The traffic class commands can be used in the following situations:

•You can use the filter and aggregation traffic class commands with the traffic class keys. Traffic class keys are specified, but they will be used only if the traffic class aggregation access list does not have any matches. In this situation, some knowledge of the prefixes that OER will learn is presumed.

•You can also use this task without the traffic class commands that use the filter and aggregation access lists, if you do not want to filter or aggregate any traffic classes. In this situation, no knowledge of the prefixes is presumed and only the traffic class command that specifies the keys is used.

In Cisco IOS Release 12.4(9)T and 12.2(33)SRB the ability to learn traffic using protocol, port number, and DSCP value (in addition to prefix) was introduced. Specifying the protocol, ports, and DSCP value allows application traffic to be identified in more detail. In this task, only traffic class keys are specified for voice traffic. The voice application traffic is identified by the UDP protocol, a DSCP value of ef, and port numbers in the range from 3000 to 4000. The master controller is also configured to learn the top prefixes based on highest outbound throughput for the specified traffic and the resulting traffic classes are added to the OER application database to be passively and actively monitored.

Exits OER Top Talker and Top Delay learning configuration mode, and returns to privileged EXEC mode.

Creating an Access List to Specify a Filter for Automatically Learned Application Traffic

Perform this task at the master controller to create an access list to filter specific application traffic for OER monitoring. In Cisco IOS Release 12.4(9)T and 12.2(33)SRB the ability to learn traffic using protocol, port number, and DSCP value (in addition to prefix) was introduced. Specifying the protocol, ports, and DSCP value allows application traffic to be identified in more detail.

In the Specifying the Flow Keys for Automatic Learning of Application Traffic Classes task, traffic keys were used to identify application traffic because no knowledge of any of the prefixes was assumed. If you know some prefixes that you want to exclude, then you can use this task to create an access list and filter out unwanted traffic. In this example for Voice traffic, the access list, VOICE_FILTER_LIST, configures OER to identify all UDP traffic from any source to a destination prefix of 10.1.0.0/16 with a DSCP value of ef that represents voice traffic. The access list is applied using a traffic class command that filters out unwanted traffic. The master controller is also configured to learn the top prefixes based on highest outbound throughput for the filtered traffic and the resulting traffic classes are added to the OER application database to be passively and actively monitored.

Perform this task at the master controller to create an access list to aggregate learned application traffic for OER monitoring. In Cisco IOS Release 12.4(9)T and 12.2(33)SRB the ability to learn traffic using protocol, port number, and DSCP value (in addition to prefix) was introduced. Specifying the protocol, ports, and DSCP value allows application traffic to be identified in more detail.

In the Creating an Access List to Specify a Filter for Automatically Learned Application Traffic task, the application traffic was filtered to profile traffic for a specific destination prefix, but in this task, the application traffic is being aggregated for a range of destination ports. In this example, the access list, VOICE_AGG_LIST is configured to aggregate traffic with a destination port in the range from 3000 to 4000 and with a DSCP value of ef. This UDP traffic represents voice traffic and OER will create traffic classes based on the specified port number range and DSCP value. In this task, the master controller is also configured to learn the top prefixes based on highest outbound throughput for the aggregated traffic and the resulting traffic classes are added to the OER application database to be passively and actively monitored.

•The example is configured to identify all UDP traffic ranging from a destination port number of 3000 to 4000 from any source where the DSCP bit is set to ef. This specific UDP traffic is to be optimized.

Supports aggregation of traffic classes during OER passive monitoring by using an extended access list.

•The example configures learned prefixes to be aggregated using the access list named VOICE_AGG_LIST that was created in Step 3 of this task.

Step 14

end

Example:

Router(config-oer-mc-learn)# end

Exits OER Top Talker and Top Delay learning configuration mode, and returns to privileged EXEC mode.

Step 15

show oer master

Example:

Router# show oer master

(Optional) Displays information about the status of the OER-managed network; the output includes information about the master controller, the border routers, OER managed interfaces, and default and user-defined policy settings.

Examples

The following example output for the show oer master command displays the additional configuration for the traffic class aggregation, filters, and key list under the Learn Settings section.

Router# show oer master

OER state: ENABLED and ACTIVE

Conn Status: SUCCESS, PORT: 7777

Version: 2.0

Number of Border routers: 2

Number of Exits: 2

Number of monitored prefixes: 0 (max 5000)

Max prefixes: total 5000 learn 2500

Prefix count: total 0, learn 0, cfg 0

Border Status UP/DOWN AuthFail Version

1.1.1.2 ACTIVE UP 00:18:57 0 2.0

1.1.1.1 ACTIVE UP 00:18:58 0 2.0

Global Settings:

max-range-utilization percent 20 recv 20

mode route metric bgp local-pref 5000

mode route metric static tag 5000

trace probe delay 1000

logging

Default Policy Settings:

backoff 180 200 180

delay relative 50

holddown 300

periodic 0

probe frequency 56

mode route control

mode monitor active

mode select-exit good

loss relative 10

jitter threshold 20

mos threshold 3.60 percent 30

unreachable relative 50

resolve delay priority 11 variance 20

resolve utilization priority 12 variance 20

*tag 0

Learn Settings:

current state : STARTED

time remaining in current state : 70 seconds

throughput

no delay

no inside bgp

traffic-class filter access-list voice-filter-acl <----

traffic-class aggregate access-list voice-agg-acl <----

traffic-class keys protocol dscp dport <----

no protocol

monitor-period 2

periodic-interval 1

aggregation-type prefix-length 24

prefixes 10

expire after time 720

Displaying Application Traffic Flow Information on a Border Router

Perform this task to display application traffic flow information. These commands are entered on a border router through which the application traffic is flowing. The commands can be entered in any order. Keywords in Step 2 and Step 4 require the border router to be running Cisco IOS Release 12.4(9)T, 12.2(33)SRB, 12.2(33)SXH, or later releases.

Prerequisites

This task requires the master controller and border routers to be running Cisco IOS Release 12.4(9)T, 12.2(33)SRB, or later releases.

This is a NetFlow command that is used to display all the flows (including applications) currently active on the border router. The following example displays traffic flow statistics by protocol, source address, and destination:

This command is used to display real-time prefix information collected from the border router through NetFlow passive monitoring. Using the learned and applications keywords you can display information about learned applications. In the output you can see that only application traffic classes matching the traffic class keys, filter, and aggregation criteria set in the first three tasks under the "Specifying the Flow Keys for Automatic Learning of Application Traffic Classes" task are saved in the learn cache.

What To Do Next

Manually Selecting Prefixes for OER Monitoring

Perform this task to manually select prefixes for monitoring. An IP prefix list is created to define the prefix or prefix range. The prefix list is then imported into the central policy database by configuring a match clause in an OER map. For details about using IP prefix lists with OER, see the "Prefix Traffic Class Configuration Using OER" section.

OER Map Operation for the OER Profile Phase

An OER map may appear to be similar to a route map but there are significant differences. An OER map is configured to select an IP prefix list using a match clause. The OER map is configured with a sequence number like a route map, and the OER map with the lowest sequence number is evaluated first. The operation of an OER map differs from a route map at this point. There are two important distinctions:

•Only a single match clause may be configured for each sequence. An error message will be displayed on the console if you attempt to configure multiple match clauses for a single OER map sequence.

•An OER map is not configured with permit or deny statements. However, a permit or deny sequence can be configured for an IP traffic flow by configuring a permit or deny statement in an IP prefix list and then applying the prefix list to the OER map.

•A master controller can monitor and control an exact prefix of any length including the default route. The master controller acts only on the configured prefix.

•A master controller can monitor and control an inclusive prefix using the le 32 option. The master controller acts on the configured prefix and forces any more specific prefixes in the RIB to use the same exit.

Note This option should be applied carefully. It is not needed in typical deployments.

•The example creates an IP prefix list for OER to monitor and control the exact prefix, 10.1.5.0/24

Step 4

oer-map map-namesequence-number

Example:

Router(config)# oer-map IMPORT 10

Enters OER map configuration mode to create or configure an OER map.

•Only a single match clause can be configured for each OER map sequence.

What to Do Next

Manually Selecting Inside Prefixes for OER Monitoring

In Cisco IOS Release 12.4(9)T, 12.2(33)SRB, and later releases, the OER BGP inbound optimization feature introduced the ability to manually select inside prefixes to support best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system. Perform this task to manually select inside prefixes for OER monitoring by creating an IP prefix list to define the inside prefix or prefix range. The prefix list is then imported into the MTC list by configuring a match clause in an OER map. For details about using IP prefix lists with OER, see the "Prefix Traffic Class Configuration Using OER" section.

OER Inside Prefixes

An OER inside prefix is defined as a public IP prefix assigned to a company. An OER outside prefix is defined as a public IP prefix assigned outside the company. Companies advertise the inside prefixes over the Internet using an Internet service provider (ISP) and receive advertisements for outside prefixes from an ISP.

OER Map Operation for Inside Prefixes

The operation of an OER map is similar to the operation of a route-map. An OER map is configured to select an IP prefix list or OER learn policy using a match clause and then to apply OER policy configurations using a set clause. The OER map is configured with a sequence number like a route-map, and the OER map with the lowest sequence number is evaluated first. In Cisco IOS Release 12.4(9)T and 12.2(33)SRB, the inside keyword that identifies inside prefixes was added to the match ip address (OER) command.

Prerequisites

This task requires the master controller and border routers to be running Cisco IOS Release 12.4(9)T, 12.2(33)SRB, or later releases.

•A master controller can monitor and control an exact prefix of any length including the default route. The master controller acts only on the configured prefix.

•A master controller can monitor and control an inclusive prefix using the le 32 option. The master controller acts on the configured prefix and forces any more specific prefixes in the RIB to use the same exit.

Note This option should be applied carefully. It is not needed in typical deployments.

•The example creates an IP prefix list for OER to monitor and control the exact prefix, 192.168.1.0/24

Step 4

oer-map map-namesequence-number

Example:

Router(config)# oer-map INSIDE_MAP 10

Enters OER map configuration mode to create or configure an OER map.

•OER map operation is similar to that of route maps.

•Only a single match clause can be configured for each OER map sequence.

•Common and deny sequences should be applied to lowest OER map sequence for best performance.

Perform this task to manually select traffic classes using prefixes, protocols, port numbers, and DSCP value for OER monitoring. An IP access list is created to define the parameters to identify the traffic classes. The access list can then be imported into the MTC list by configuring a match clause in an OER map.

This example task uses an access list to identify voice traffic. Before voice traffic can be optimized, it must be identified. In this task, the voice traffic that is to be optimized is identified by a protocol of UDP, a range of source and destination port numbers from 16384 to 32767, a destination prefix of 10.20.20.0/24, and a DSCP value of ef.

IP Protocol Stack for Voice

Voice traffic uses a variety of protocols and streams on the underlying IP network. Figure 3 is a representation of the protocol options available for carrying voice traffic over IP. Most signaling traffic for voice is carried over TCP. Most voice calls are carried over User Datagram Protocol (UDP) and Real-Time Protocol (RTP). You can configure your voice devices to use a specific range of destination port numbers over UDP to carry voice call traffic.

Figure 3 Protocol Stack Options Available for Voice Traffic

Prerequisites

This task requires the master controller and border routers to be running Cisco IOS Release 12.4(9)T, 12.2(33)SRB, or later releases.

•The example is configured to identify all UDP traffic with a source or destination port number in the range from 16384 to 32767 from any source prefix to a destination prefix of 10.20.20.0/24, and with a DSCP value of ef. This specific UDP traffic represents voice traffic.

The following example, starting in global configuration mode, configures the master controller to automatically learn top prefixes based on the highest delay. The prefix monitoring period is set to 10 minutes. The number of prefixes that are monitored during each monitoring period is set to 500. The time interval between each monitoring period is set to 20 minutes.

The following example, starting in global configuration mode, configures the master controller to automatically learn defined application traffic. Using a series of traffic class commands under OER learn configuration mode, only voice traffic with a DSCP bit set to ef, a protocol of UDP, and a destination port in the range of 3000 to 4000 is learned and added to the OER MTC list on the master controller.

The prefix monitoring period is set to 2 minutes. The number of prefixes that are monitored during each monitoring period is set to 10. The time interval between each monitoring period is set to 20 minutes.

More details about the OER network configuration for the example shown above can be seen in the running configuration file:

Router# show running-config

oer master

port 7777

logging

!

border 10.1.1.1 key-chain key1

interface Serial12/0 external

interface Ethernet8/0 internal

!

border 10.1.1.2 key-chain key2

interface Ethernet0/0 external

interface Ethernet8/0 internal

!

learn

throughput

periodic-interval 1

monitor-period 2

prefixes 10

traffic-class filter access-list voice-filter-acl

traffic-class aggregate access-list voice-agg-acl

traffic-class keys protocol dscp dport

backoff 180 200

mode route control

mode monitor active

!

active-probe echo 10.1.2.1

active-probe echo 10.1.1.1

active-probe echo 10.1.3.1

Manually Selecting Prefixes for OER Monitoring: Example

The following example, starting in global configuration mode, configures an OER map to exclude traffic from the 192.168.0.0/16 network and include traffic from the 10.5.5.0/24 network. Excluded prefixes are not imported into the MTC list.

The following configuration is performed on an edge router which is both an OER master controller and a border router (for example, in a remote office network) to identify voice traffic using an extended named access list.

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Feature Information for Using OER to Profile the Traffic Classes

Table 1 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Release 12.3(11)T, 12.2(33)SRB, or a later releaseappear in the table.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

Table 1 Feature Information for Using OER to Profile the Traffic Classes

Feature Name

Releases

Feature Configuration Information

Port and Protocol Based Prefix Learning

12.3(11)T12.2(33)SRB

Port and protocol based prefix learning allows you to configure a master controller to learn prefixes based on the protocol type and TCP or UDP port number.

The expire command is used to set an expiration period for learned prefixes. By default, the master controller removes inactive prefixes from the central policy database as memory is needed. This command allows you to refine this behavior by setting a time or session based limit. The time based limit is configured in minutes. The session based limit is configured for the number of monitor periods (or sessions).

OER Application-Aware Routing: PBR

12.4(2)T12.2(33)SRB

The OER Application-Aware Routing: PBR feature introduces the capability to optimize IP traffic based on the type of application that is carried by the monitored prefix. Independent policy configuration is applied to the subset (application) of traffic.

OER BGP inbound optimization supports best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system. External BGP (eBGP) advertisements from an autonomous system to an Internet service provider (ISP) can influence the entrance path for traffic entering the network. OER uses eBGP advertisements to manipulate the best entrance selection.

OER DSCP Monitoring introduced automatic learning of traffic classes based on protocol, port numbers, and DSCP value. Traffic classes can be defined by a combination of keys comprising of protocol, port numbers, and DSCP values, with the ability to filter out traffic that is not required, and the ability to aggregate the traffic in which you are interested. Layer 4 information such as protocol, port number, and DSCP information is now sent to the master controller database in addition to the Layer 3 prefix information. The new functionality allows OER to both actively and passively monitor application traffic.

The following commands were introduced or modified by this feature: show oer border passive applications, show oer border passive cache, show oer border passive learn, show oer master appl, traffic-class aggregation, traffic-class filter, and traffic-class keys.

OER Border Router Only Functionality

12.2(33)SXH

In Cisco IOS Release 12.2(33)SXH support for using a Cisco Catalyst 6500 series switch as an OER border router was introduced. Only border router functionality is included in the Cisco IOS Release 12.2(33)SXH images; no master controller configuration is available. The master controller that communicates with the Cisco Catalyst 6500 series switch being used as a border router must be a router running Cisco IOS Release 12.4(6)T or a later release. The OER master controller software has been modified to handle the limited functionality supported by the Cisco Catalyst 6500 border routers. Using the Route Processor (RP), the Catalyst 6500 border routers can capture throughput statistics only for a traffic class compared to the delay, loss, unreachability, and throughput statistics collected by non-Catalyst 6500 border routers. A master controller automatically detects the limited capabilities of the Catalyst 6500 border routers and downgrades other border routers to capture only the throughput statistics for traffic classes. By ignoring other types of statistics, the master controller is presented with a uniform view of the border router functionality.

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